Process for distributing a resin in a fabric



United States Patent Ofi ice 3,476,580 Patented Nov. 4, 1969 3,476,580PROCESS FOR DISTRIBUTING A RESIN IN A FABRIC Allen J. Jinnette,Greensboro, N.C., assignor to Burlington Industries, Inc., Greensboro,N.C., a corporation of Delaware No Drawing. Filed Oct. 24, 1966, Ser.No. 588,697 Int. Cl. B44d 1/44; C03c 13/00 US. Cl. 117-62 13 ClaimsABSTRACT OF THE DISCLOSURE In the dyeing of textile fabrics,particularly glass fiber textiles, uniformity and penetration of thecoloring material throughout the fabric or yarn is achieved by providinga uniform distribution of resinous material throughout the fabric oryarn by the process comprising mixing a neutralized polyamide with saidresinous material, applying the mixture so obtained to said fabric oryarn, and subsequently heating the fabric or yarn which contains theresinous material thereon to cause said polyamide to revert to anunneutralized state, whereby said resinous material is coagulated.

This invention relates to the treatment of textile fabrics. Theinvention is of particular importance in the dyeing of glass textiles.

BACKGROUND OF THE INVENTION Prior art processes for dyeing glasstextiles involve the use of pigments which are dispersed in resinemulsions, the dispersion being applied to the fabric by padding. Onesuch prior art process is described in the Hamiter et al. Patent, No.3,108,897, issued Oct. 27, 1963, the disclosure of which is herebyincorporated by reference. The Hamiter et a1. patent uses a dye bathcontaining an anionic resinous binder and a flocculated pigment. Afterthe dye bath is padded onto the fabric, the fabric is heated to cure theresin, thereby afiixing the pigment onto the glass fabric.

The prior art has recognized the desirability in the dyeing of glasstextiles, that is, glass fabrics or yarns made from glass fibers orfilaments, that each filament of the fabric should be coated withpigmented resin to achieve a uniform coloring effect.

The Hamiter et a1. process and other prior art processes for dyeing andfinishing glass textiles do not achieve uniform color throughout theglass textile because the pigments and resins coated on the glass yarnstend to migrate to the surface of the textile during the drying step.This migration of pigments and resins tends to leave the interstices ofthe fabrics and the inside of the filament bundles of the individualyarns uncolored. When the yarns in the fabric are shifted, such as byabrasion during normal wear or use or on washing, the uncolored portionsof the fabric or the yarn may be exposed to produce an objectionableeffect.

Various agents, such as Kelsize, cellulose ethers or esters, naturalgums, acrylic polymers, etc., have been employed in an effort to controlmigration of pigments in the dyeing process. These agents apparentlyderive their anti-migration effect by increasing the viscosity of thepadding liquor. However, when the viscosity of the padding liquor isthus increased, there is a corresponding decrease in the penetrationpower of the padding liquor, i.e., the higher the viscosity of thepadding liquor, the less the inside surfaces of the fabrics and theyarns tend to be covered by the pigmented liquor.

OBJECTS OF THE INVENTION It is an object of the present invention toprovide a novel process for the treatment of textile materials.

It is another object of the present invention to provide a novel processfor the penetration dyeing of textile fabrics.

It is yet another object of the present invention to provide a novelprocess for the penetration dyeing of glass textiles.

It is a further object of the present invention to provide a novelprocess for the dyeing of glass fabrics which results in increaseduniformity in the distribution of the coloring material throughout thefabric.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter; it should be understood, however, that the detaileddescription and specific examples, while indicating preferredembodiments of the invention, are given by way of illustration only,since various changes and modifications within the spirit and scope ofthe invention will become apparent to those skilled in the art from thisdetailed description.

SUMMARY OF THE INVENTION In accordance with the present invention, theabove objects are accomplished by including neutralized polyamides inthe resinous dye bath. During a heating step, subsequent to a dye bathpadding step, which is conventionally used to cure the resins present inthe dye bath, the neutralized polyamide is converted into the originalpolyamide compound, which fixes the pigment/resin dispersion. Suchfixing of the pigment/resin dispersion fixes the position of the pigmentwithin the fiber bundles, thereby eliminating subsequent pigmentmigration.

DESCRIPTION OF THE INVENTION The process of the present inventionprovides for the inclusion of a neutralized polyamide in a pigmented dyebath or an unpigmented resinous bath. By the term polyamide, when usedin the present application, it is meant those cation activepolyelectrolytes or cationic resinous compounds which are alsoamino-functional. These compounds are chemically identifiable as lowmolecular weight water-soluble polyamine acrylamides, e.g., the reactionproduct of a low molecular weight polymethacrylate or polyethylacrylatewith a polyamine such as triethylene tetramine, having two or more aminogroups, at least one of which is a primary amino. This type of reactionproduct is disclosed in U. S. Patent 2,675,359. Molecular weights in therage of 2000 to 5000 may be mentioned as illustrative although productsof higher molecular weights, e.g., 10,000 or above, may also be used.Compounds of this type which are commercially available include theproducts known as Nalco 600 (National Aluminate Corporation) and QR-419(Rohm & Haas). Other cationic resinous compounds useful herein includethe water-soluble, cationic condensation products of formaldehyde anddicyandiamide or similar compounds containing the grouping wherein thefree valences are satisfied by hydrogen, lower alkyl, phenyl or otheraryl radicals. A typical example of such a condensation product usefulherein is methylol guanidine.

The preferred polyamide is the compound commercially available as Nalco600. This compound and other polyamides can be neutraized by theaddition of a strong volatile organic acid under conditions which favorthe reaction of the polyamide and the acid. Generally, the materialswill react at room conditions but heating to a temperature of 100 to 120F. for a time of 1 to minutes is preferred. The final product shouldhave a pH within the range of 2.5 to 6, and preferably the pH is withinthe range of 4 to 5. Acetic acid is the preferred neutralizing acid, butformic acid and acrylic acid may be used in lieu thereof, as well asother strong, volatile acids which will neutralize the primary aminegroups within the polyamide.

Before the polyamides are neutralized, they possess the ability toflocculate pigments and to aid in the coagulation in the binder resinsin the dye bath. This fiocculating and coagulating property of thepolyamides is inhibited by the neutralization step, but the property canbe regenerated when heat causes the neutralized compound to revert backto the acid and the polyamide. Generally, it is preferred for theneutralizing acid to be evaporated during the heating, or fixing, step.Although the neutralized polyamides will function at any acid pH, a pHof 4 to 5 is preferred.

In dyeing glass fibers, a binder is commonly employed to cause aphysical adherence between the coloring agent and the glass. The binderis generally a resinous material such as polyacrylic latex, certain ofthe silicones, polyvinyl alcohol or polyvinyl acetate, etc. Additionalresinous materials which may be used in the process of this inventionare disclosed in the Hamiter et al. Patent, 3,108,897.

It has been found highly advantageous to include in the pad compositiona silane crosslinking agent containing a reactive grouping. The functionof this crosslinking agent is to anchor the resin to the glass surface.Additionally, however, the silane serves as an anchoring agent andcatalyst for a subsequently applied top finishing binder system. Thesilane crosslinking agent used herein may be an aminolykyl trialkoxysilane containing at least one amino group and up to about carbon atoms,exclusive of those in the alkoxy groups attached to the silicon atom,each alkoxy group containing from 1-3 carbon atoms. Best results areobtainable with aliphatic silanes containing one or more secondarygroups or both primary and secondary groups. Typical examples of suchcompounds are those represented by the formula:

wherein m and n are integers from 1 to 4, preferably 2 to 3, R is alkylcontaining from 1 to 3 carbon atoms and R is hydrogen, methyl or ethyl.An especially preferred silane is N-(Z-aminoethyl)-3-propylaminotrimethoxy silane represented structurally as and commercially availableas Z-6020 or A-1100. An acrylic modification of Z-6020, available asXZ-8-4032, may also be mentioned as a specific illustration of a silaneuseful, as well as gamma-aminopropyl triethoxy silane.

It has also been found desirable to include an epoxy resin and/ or epoxyoil compounds in the pigmented coating composition. Epoxy resinsgenerally are suitable for this purpose but the preferred epoxies arethose which can react with the silane crosslinking agent. Examples ofsuitable epoxies include the bisphenolepichlorhydrin type and epoxidizedoils, e.g. epoxy soybean oil or the like.

The pigment to be used in the process of the present invention must beselected from those which are stable throughout the processing steps,i.e. the pigment must be able to withstand the curing temperatureWithout change. These pigments are well known to those skilled in theart. Examples of the inorganic pigments which can be used are theoxides, sulfites and sulfates of cobalt, chromium, iron, zinc andcadmium, etc. Examples of organic pigments are the azo coupling dyes,anthraquinone, phthalocyanine, indanthrene vat dyes and carbon black,etc. The dye bath generally contains about 0.5 to 5% by weight ofpigment but more or less pigment can be used as desired. The pigment isusually employed in the form of an aqueous dispersion, which includeswater, pigment and a dispersing agent, as is known to the prior art.

The glass fibers treated herein may be of any conventional composition.Typically suitable fibers are those made from glass of the followingapproximate composi-- tion wherein parts are by weight.

Parts Silicone dioxide 52-56 Calcium oxide 16-25 Aluminum oxide 12-16Boron oxide 8-13 Na O sodium oxide 0-1 Magnesium oxide 0-6 Othersuitable glass compositions are shown, for example, in US. Patents2,582,919 and 3,011,929.

While the present invention is not to be limited to any particulartheory of reaction or mechanism, it is believed that the heating stepcauses water and acetic acid to evaporate from the textile material,thus causing the pH of the remaining liquid in the fabric to rapidlyrise. Due to the loss of acetic acid, with the consequentialregeneration of the primary amine groups in the free state, the cationicnature of the polyelectrolyte is restored and causes a coagulation ofthe resin and/or flocculation of the pigment within the filament bundlesof the glass yarns. This coagulation and/or flocculation prevents themigration of the resin and any pigments present during subsequentoperations, thereby producing a level dyeing throughout each individualglass yarn in the fabric.

The invention is illustrated but not limited by the following exampleswherein parts and percentages unless otherwise stated, are by weight.

Example I A fabric woven with glass E yarn in both warp and filling wasfirst heat cleaned using the process shown in US. Patent 2,970,934. Theheat cleaning process of US. Patent 3,012,848 could also be used withequal effect.

The heat cleaned fabric was then immersed in a dye bath made up asfollows:

To a small quantity of water was added the following materials:

/2% silicone XZ8-4032 1% Nalco 600 (neutralized to pH 5 with aceticacid) 4 /2% acrylic resin emulsion 1% epoxy resin emulsion 4% epoxysoybean oil emulsion 2% acetic acid (final bath pH of 4) The neutralizedNalco 600' was prepared by reacting the Nalco 600 with an amount ofacetic acid sufficient to give a final reaction product pH of 5. Thereaction occurred at atmospheric pressure by heating the admixedmaterials to a temperature of F. for 3 minutes.

All percentages in this example were based on the final weight of thedye bath. To the above mixture was then added 1% of an aqueousdispersion of pigment padding Brown R (Interchemical Corporation). Thepigmeat dispersion was added to the mixture with vigorous stirring andadditional water was added to bring the dye bath mixture to the finalcomposition (total solids of 9% by weight).

The above dye bath was then padded onto heat cleaned glass cloth and thefabric was then dried with sufficient heat to cure the resins (340 F.for 2 minutes).

After the fabric was treated with dye bath composition it was given atop finish. The composition used for top finish was:

1% XZ8-40-32 silicone 8% Acrylic resin emulsion 8% Epoxy oil emulsion 3Epoxy resin emulsion 2 /2 Quilon Water to make 100% Quilon is a chromecomplex such as described in US. Patents 2,356,161 and 2,273,040. Thisfinish was also padded onto the fabric and dried and cured.

The glass fabric dried according to the above pro.- cedure was found tohave good dye penetration, good dye fixation, and good color fastnessthrough repeated washing.

Although the preferred embodiment of the present invention is in thepenetration dyeing of glass textiles, it is clear that the process ofthis invention may be used whenever a uniform distribution of a resinousmaterial is desired throughout a textile fabric. The process of thepresent invention was found to give excellent dye penetration, dyefixation and wash fastness on fabrics other than fiber glass, forexample, on cotton and rayon fabrics, etc. The process of the presentinvention was also effective in preventing the migration of unpigmentedresins applied upon glass textiles and other types of fabrics.

The dried glass fabric may be given a dulling treatment with oxalic acidprior to the top finishing step. The dulling treatment with oxalic acidis described in co-pending application Ser. No. 266,013 now US. Patent3,259,517 assigned to Burlington Industries, the disclosure of which ishereby incorporated by reference. This dulling treatment produces thedesired degree of dullness or opacity in the fabric. This treatment alsoimproves the abrasion resistance and tensile strength of the driedfabric. The dulling treatment is preferably applied to the fabric afterthe dyeing step but before the top finishing process.

Although the amounts of the various constituents in the dye bath may bevaried over wide ranges, generally the dye bath will contain about 2 toby weight of binder resin, and about 0.5 to 3% by weight of pigment. Theamount of pigment used is only limited by the carrying ability of theresin system. In order for larger amounts of pigment to be used, anincrease in the resin content of the dye bath is generally necessary.Such resin content increase in the dye bath affects the hand and drapeof the final product.

The amount of neutralized poly-amide which can be used in the dye bathwill vary over very wide ranges. It is generally preferred to use anamount of the polyamide which, in the unneutralized state, will be inexcess of the amount required to flocculate the pigment in the dye bath,but a great excess over this preferred minimal amount of neutralizedpolyamide may be used. Generally, it is preferred that the amount ofneutralized polyamide used be within the range of 0.5 to 1.5% by weightof the dye bath, although it is to be understood that this range is onlyto indicate the most desirable range and is not by the way oflimitation.

Since the neutralized Nalco 600 is preferably used at a pH of 4 to 5, itis preferred to use pigment dispersions and resin emulsions which arestable at these pH values in order to give best results.

By the process of the invention dried glass fabrics were obtained whichhad a good hand, excellent wash fastness, excellent hem-line abrasionresistance and excellent dye penetration throughout the fabrics. Whenthe threads in the fabrics were shifted, there were exposed noobjectionable undyed areas such as would happen with conventional dyeingprocesses. Examination of yarn dyed according to the present processshows the dyeresin mixture to have penetrated the yarn bundles and thefabric throughout. Furthermore, the dye/resin mixtures which havepenetrated the yarn bundles showed no appreciable migration during thecuring step, thus yielding a product having excellent pigmentdistribution. Equally good results were obtained when the process wastried on fabrics other than fiber glass, e.g. cotton and rayon goods,etc.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that the invention may be practiced otherwise than asspecifically de scribed.

What is claimed is:

1. A process for uniformly distributing a resinous material throughoutfabric or yarn, said process comprising mixing a neutral salt of apolya-mino-polyamide and a volatile organic acid with a dispersion of acoagulable resinous material and water, applying the mixture obtained tosaid fabric or yarn, and subsequently heating the fabric or yarn whichcontains the aforesaid mixture of resinous material andpolyamino-polyamide salt therein to a temperature of at least 250 F. toregenerate the free polyamino-polyamide thereby causing the coagulationof the resinous material.

2. The process as claimed in claim 1 wherein said mixture of a neutralsalt of a polyamino-polyamide and a volatile organic acid and acoagulable resinous material contains a pigment and a liquid vehicle.

3. The process as claimed in claim 2 wherein said textile material isselected from the group consisting of cotton and rayon.

4. The process as claimed in claim 2 wherein said mixture of a neutralsalt of a polyamino-polyamide and a volatile organic acid and acoagulable resinous material containing a pigment and a liquid vehicleadditionally includes a reactive amino-silane.

5. The process as claimed in claim 4 wherein said mixture of a neutralsalt of a polyamide-polyamide and a volatile organic acid and acoagulable resinous material containing pigment and a liquid vehicleadditionally includes an epoxy compound.

6. The process as claimed in claim 2 wherein said fabric or yarn is aglass textile.

7. The process as claimed in claim 6 further comprising treating saidglass textile, after the cogaulated resin has been cured thereon, withan oxalic acid-dulling treatment and thereafter coating said dulled.glass fabric with a top finish composition.

8. The process as claimed in claim 6 further comprising treating saidglass textile after said resin had been cured thereon with a top finishcomposition.

9. The process as claimed in claim 2 wherein said neutralized polyamideis prepared by reacting a p0lyaminopolyamide with a strong, volatileorganic acid.

10. The process as claimed in claim 9 wherein said polyamide is awater-soluble cation active polyelectrolyte.

11. The process as claimed in claim 9 wherein said polyamide is awater-soluble polyamino-polyamide.

12. The process as claimed in claim 9, wherein said polyamino-polyamideis reacted with a sufficient amount of said acid to result in -a saltwith a final pH of about 4 to about 5.

13. The process as claimed in claim 12 wherein said 3,223,551 12/1965 Tu11762.1 X volatile acid is selected from the group consisting of3,259,517 7/ 1966 Atwell 117126X acetic acid, formic acid and acrylicacid. $285,775 11/1966 Tu References Cited 5 WILLIAM D. MARTIN, PrimaryExaminer UNITED STATES PATENTS D. COHEN, Assistant Examiner 2,260,87110/1941 Sawyer 106-309 X US. Cl. X.R. 2,689,193 9/1954 LipsOn et al1l762. 1

117161, 145, 143, 126, 76, 38, 62.1 3,108,897 10/1963 Hamiter et a1.l17-37

